Assessing the effects of Bt maize on the non-target pest Rhopalosiphum maidis by demographic and life-history measurement endpoints.

AbstractThe most commercialized Bt maize plants in Europe were transformed with genes which express a truncated form of the insecticidal delta-endotoxin (Cry1Ab) from the soil bacterium Bacillus thuringiensis (Bt) specifically against Lepidoptera. Studies on the effect of transgenic maize on non-target arthropods have mainly converged on beneficial insects. However, considering the worldwide extensive cultivation of Bt maize, an increased availability of information on their possible impact on non-target pests is also required. In this study, the impact of Bt-maize on the non-target corn leaf aphid, Rhopalosiphum maidis, was examined by comparing biological traits and demographic parameters of two generations of aphids reared on transgenic maize with those on untransformed near-isogenic plants. Furthermore, free and bound phenolics content on transgenic and near-isogenic plants were measured. Here we show an increased performance of the second generation of R. maidis on Bt-maize that could be attributable to indirect effects, such as the reduction of defense against pests due to unintended changes in plant characteristics caused by the insertion of the transgene. Indeed, the comparison of Bt-maize with its corresponding near-isogenic line strongly suggests that the transformation could have induced adverse effects on the biosynthesis and accumulation of free phenolic compounds. In conclusion, even though there is adequate evidence that aphids performed better on Bt-maize than on non-Bt plants, aphid economic damage has not been reported in commercial Bt corn fields in comparison to non-Bt corn fields. Nevertheless, Bt-maize plants can be more easily exploited by R. maidis, possibly due to a lower level of secondary metabolites present in their leaves. The recognition of this mechanism increases our knowledge concerning how insect-resistant genetically modified plants impact on non-target arthropods communities, including tritrophic web interactions, and can help support a sustainable use of genetically modified crops

Characterization of COVID-19-related lung involvement in patients undergoing magnetic resonance T1 and T2 mapping imaging: a pilot study

Tissue characterization by mapping techniques is a recent magnetic resonance imaging (MRI) tool that could aid the tissue characterization of lung parenchyma in coronavirus disease-2019 (COVID-19). The aim of the present study was to compare lung MRI findings, including T1 and T2 mapping, in a group of n = 11 patients with COVID-19 pneumonia who underwent a scheduled cardiac MRI, and a cohort of healthy controls. MRI scout images were used to identify affected and remote lung regions within the patients’ cohort and appropriate regions of interest (ROIs) were drawn accordingly. Both lung native T1 and T2 values were significantly higher in the affected areas of patients with COVID-19 as compared to the controls (1375 ms vs. 1201 ms, p = 0.016 and 70 ms vs. 30 ms, p < 0.001, respectively), whereas no significant differences were detected between the remote lung parenchyma of the COVID-19 patients and the controls (both p > 0.05). When a larger ROI was identified, comprising the whole lung parenchyma within the image irrespective of the affected and remote areas, the COVID-19 patients still retained higher native T1 (1278 ms vs. 1149 ms, p = 0.003) and T2 values (38 ms vs. 34 ms, p = 0.04). According to the receiver operator characteristics curves, the T2 value of the affected region retained the higher accuracy for the differentiation of the COVID-19 patients against the controls (area under the curve 0.934, 95% confidence interval 0.826–0.999). These findings, possibly driven by the ability of MRI tissue mapping to detect ongoing inflammation in the lungs of patients with COVID-19, suggest that T1 and T2 mapping of the lung is a feasible approach in this clinical scenario

T1 and T2 Mapping in Uremic Cardiomyopathy: An Update

Uremic cardiomyopathy (UC) is the cardiac remodelling that occurs in patients with chronic kidney disease (CKD). It is characterised by a left ventricular (LV) hypertrophy phenotype, diastolic dysfunction and generally preserved LV ejection fraction. UC has a major role mediating the increased rate of cardiovascular events, especially heart failure related, observed in patients with CKD. Recently, the use of T1 and T2 mapping techniques on cardiac MRI has expanded the ability to characterise cardiac involvement in CKD. Native T1 mapping effectively tracks the progression of interstitial fibrosis in UC, whereas T2 mapping analysis suggests the contribution of myocardial oedema, at least in a subgroup of patients. Both T1 and T2 increased values were related to worsening clinical status, myocardial injury and B-type natriuretic peptide release. Studies investigating the prognostic relevance and histology validation of mapping techniques in CKD are awaited

Modeling Green Peach Aphid populations exposed to elicitors inducing plant resistance on peach

Matrix Population Models (MPMs) are not commonly used to simulate arthropod population dynamics with applications to pest control assessment in agricultural context. However, an increasing body of studies are prompting the finding of optimization techniques to reduce uncertainty in matrix parameters estimation. Indeed, uncertainty in parameters estimates may lead to significant management implications. Here we present a case study where MPMs are used for assessing the efficacy of treatment with elicitors inducing plant resistance against pathogen, such as laminarin, for the control of the Green Peach Aphid (Myzus persicae Sulzer) populations on peach. Such demographic approach could be particularly suitable to study this kind of compounds, which are mainly characterized by causing sub-lethal effects rather than acute mortality. An artificially assembled system [1] was arranged since it is well suited to follow the fate and behavior of a population exposed to elicitors activating chemical defense in plant. The obtained data, consisting of population time series, were used to generate a stage-classified projection matrix. The general model used to simulate population dynamics consists of a matrix containing i) survival probabilities (the probability of growing and moving to the next stage and the probability of surviving and remaining in the same stage), and ii) fecundities of the population. Most of the used methods for estimating the parameter values of stage-classified models rely on following cohorts of identified individuals [2]. However, in this study the observed data consisted of a time-series of population vectors where individuals are not distinguished. The relationship between the observed data and the values of the matrix parameters that produced the series involves an estimation process called inverse problem. Since all demographic analyses rely on how much the estimated parameters of the matrix are able to represent population dynamics, a Genetic algorithm for inverse parameter estimation was used in order to find a better model fit for the observed stage class distributions. These results were compared to those obtained by the quadratic programming method [3] used for determining the set of parameters that minimizes the residual between the collected data and the model output. REFERENCES: 1. Macfadyen, S., Banks, J.E., Stark, J.D., Davies, A.P., 2014. Using semifield studies to examine the effects of pesticides on mobile terrestrial invertebrates. Annu. Rev. Entomol. 59, 383-404. 2. Caswell, H., 2001. Matrix population models, second ed. Sinauer Associates Inc., Massachusetts. 3. Wood, S.N., 1994. Obtaining birth and mortality patterns from structured population trajectories. Ecol. Monogr. 64, 23-44

Exploring the influence of takotsubo syndrome on oncologic patients' mortality

It has been reported that patients affected by takotsubo syndrome (TTS) with a concurrent diagnosis of cancer suffer from greater mortality as compared to their non-cancer counterpart. It remains unclear whether TTS worsens the prognosis of cancer patients as well. Aim of this study was to compare outcomes of cancer patients with and without TTS. We combined data from two independent cohorts: one consisted of a prospective multicentre TTS registry; the second cohort consisted of all oncologic patients from two Cardio-Oncology Outpatient Clinics, who did not have cardiovascular conditions at the time of the cardio-oncologic visit. From the TTS registry, we selected patients with cancer (cancer-TTS patients). Next, we matched these patients with those from the cardio-oncologic cohort (cancer non-TTS patients) in a 1:2 fashion by age, sex, and type and cancer staging. Study endpoint was all-cause mortality. Among 318 TTS patients, 42 (13%) had a concurrent diagnosis of cancer. Characteristics of cancer-TTS patients and of the 84 matched cancer non-TTS subjects were comparable with the exception of diabetes mellitus, which was more common in cancer non-TTS patients. All-cause mortality was similar between cancer-TTS and cancer non-TTS patients. At Cox regression analysis TTS was not associated with mortality (OR 1.4, 95% CI 0.6-3.3, p = 0.43). Our findings show that even in the presence of acute heart failure due to TTS, the prognosis of oncologic patients is driven by the malignancy itself. Our results may prove useful for integrated management of cardio-oncologic patients

Cardiac magnetic resonance imaging of transient myocardial dysfunction in a patient treated with checkpoint-targeted immunotherapy

Here we report the case of a 70-year-old man presented to the emergency department because of sudden dyspnoea

Heart and lung involvement detected by native T1 and T2 mapping magnetic resonance imaging in a patient with coronavirus disease-19

A 57-year-old woman was presented to our coronavirus disease-2019 (COVID-19) dedicated coronary care unit following chest pain, fever, and concomitant increased high-sensitivity cardiac troponin

Heart and lung fibrosis in a patient with COVID-19-related myocarditis

A COVID-19 patient, in whom pneumonia lesions were first detected by chest computed tomography, was further evaluated by cardiac magnetic resonance (CMR) due to a suspected myocarditis. Beyond heart alterations, CMR revealed peculiar features of affected pulmonary areas in T1 mapping sequences and showed a particular distribution of late gadolinium enhancement in the same regions. The noninvasive assessment of the cellular, fluid, or fibrotic content of lung lesions may provide key information about the underlying pathophysiological pathways in the search of a tailored medical therapy and ventilatory support for COVID-19 patients